In an effort to curb abuse of powerful painkillers, Massachusetts's largest insurer is going to restrict doctors' ability to write new prescriptions to 30 days' worth of pills such as OxyContin and Vicodin before a mandatory review by the insurer.

Officials at Blue Cross Blue Shield of Massachusetts say the policy, which begins July 1, will prevent doctors from prescribing 60 days' worth of OxyContin, for example, for a minor problem such as a sprained ankle. Patients with such serious or chronic conditions as cancer or those who are terminally ill will be permitted to continue receiving opioid painkillers.

The insurer — the first in the nation to take this step — hopes to reduce the risk of addiction and also to keep the drugs away from people for whom they weren't prescribed. Many states, including Florida, have prescription drug monitoring programs that were set up in an effort to slow down the pill problem. An average of 8 people a day die in Florida from prescription drug abuse.

"We want to give patients an adequate supply, but not so many that it causes a problem," says John Fallon, chief physician executive at BCBS of Massachusetts.

The insurer says roughly 10 percent of its members — more than 30,000 people — have received painkiller prescriptions lasting longer than 30 days. Under the new policy, doctors can prescribe one 15-day prescription and one 15-day refill before a review is required.

"If you're going to have more than a 30-day supply, there needs to be dialogue with the patient about the risks of addiction," Fallon says.

Scott McClelland, senior director of pharmacy operations for Florida Blue, said that while that insurer does have some 30-day quantity limits, it has no across-the-board policy like the Massachusetts plan.

While agreeing that it's important to address prescription painkiller abuse, some physicians and patient advocates say they're worried the new policy will make it even tougher for patients with chronic pain — about a third of U.S. adults, according to a survey by the American Pain Society.

They point out that many of these patients already find it hard to get services they need. Physical therapy, for example, is often not adequately covered by insurance, and doctors frequently lack extensive training in pain management.